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Coupling two domain

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Hi.
I need to connect the water tank to the one rectangular micro channel.
I modeled the drain tank and solved it and it is ok. Also I modeled the micro channel separately.
Now I don't know how can I couple that tank to the micro channel ? I connected two geometries together but there is no flow in micro channel .
How can I couple two domain together?
I attached the geometries on the file.
Please guide me.
Thank you
Ashkan


4 Replies Last Post 09.07.2012, 02:17 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 23.06.2012, 13:05 GMT-4
Hi

you are not telling us enough about your 2 models, which physics ? which dependent variables ...
Basically coupling the two means getting a continuity conditions on all dependent variables from both models, this is "easy" if it is the same physics, but might need some equations if you have different dependent variables on each side

--
Good luck
Ivar
Hi you are not telling us enough about your 2 models, which physics ? which dependent variables ... Basically coupling the two means getting a continuity conditions on all dependent variables from both models, this is "easy" if it is the same physics, but might need some equations if you have different dependent variables on each side -- Good luck Ivar

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Posted: 1 decade ago 03.07.2012, 05:20 GMT-4
Hi.
Sorry for late answer.
Actually the water tank is solved by single flow and laminar flow and it solved by moving mesh for showing how water reduced inside of the tank. We set the gravity force as an effective force for draing of water from the tank and also we set the pressure zero in the outlet of water tank .
The microchannel also solved separatly in the single flow and laminar flow. for microchannel also we set the zero in the outlet and calculate the flow rate in the ending of microchannle.
Now we would like to connect the microchannel to the tank and calculate the flow rate in the ending of the microchannel.Now our outlet is in the end of the microchannel.
how can I do that.
Thank you

Hi. Sorry for late answer. Actually the water tank is solved by single flow and laminar flow and it solved by moving mesh for showing how water reduced inside of the tank. We set the gravity force as an effective force for draing of water from the tank and also we set the pressure zero in the outlet of water tank . The microchannel also solved separatly in the single flow and laminar flow. for microchannel also we set the zero in the outlet and calculate the flow rate in the ending of microchannle. Now we would like to connect the microchannel to the tank and calculate the flow rate in the ending of the microchannel.Now our outlet is in the end of the microchannel. how can I do that. Thank you

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Posted: 1 decade ago 03.07.2012, 06:41 GMT-4
More thing that can I say , that our problem is in transient form. At the begining of the time gravity force caused to draing water from the tank. In evry moment the velocity ate the outlet of tank and in the top of tant (free surface) calculated. it means the velocity is variable because it depends to the height of tank and after sometimes the velocity because of reducing of height of water decreased and also the flow rate is changing every moment and it is also variable.
In the microchannel the hydrolic resistivity is the constant and it is effective for reducing of water velocity.
I think when we connect the microchannel to the tank because of hydrolic resistivity of microchannel the draining of water from the end of microchannel should be take more time than draing from the end of the tank.
the properties and velocity of the water always is constant.
These are more information about the physics of the problem that you asked.
I will really thanks full if you help me.
Thank you in advanced
More thing that can I say , that our problem is in transient form. At the begining of the time gravity force caused to draing water from the tank. In evry moment the velocity ate the outlet of tank and in the top of tant (free surface) calculated. it means the velocity is variable because it depends to the height of tank and after sometimes the velocity because of reducing of height of water decreased and also the flow rate is changing every moment and it is also variable. In the microchannel the hydrolic resistivity is the constant and it is effective for reducing of water velocity. I think when we connect the microchannel to the tank because of hydrolic resistivity of microchannel the draining of water from the end of microchannel should be take more time than draing from the end of the tank. the properties and velocity of the water always is constant. These are more information about the physics of the problem that you asked. I will really thanks full if you help me. Thank you in advanced

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Posted: 1 decade ago 09.07.2012, 02:17 GMT-4
Any help?
please guide me.
Thank you
Any help? please guide me. Thank you

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